Iron supplementation associated with loss of phenotype in autosomal dominant hypophosphatemic rickets

Klaus Kapelari, Julia Köhle, Dieter Kotzot, Wolfgang Hoegler

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)

Abstract

CONTEXT: Autosomal dominant hypophosphatemic rickets (ADHR) is the only hereditary disorder of renal phosphate wasting in which patients may regain the ability to conserve phosphate. Low iron status plays a role in the pathophysiology of ADHR.

OBJECTIVE: This study reports of a girl with ADHR, iron deficiency, and a paternal history of hypophosphatemic rickets that resolved without treatment. The girl's biochemical phenotype resolved with iron supplementation.

SUBJECTS: A 26-month-old girl presented with typical features of hypophosphatemic rickets, short stature (79 cm; -2.82 SDS), and iron deficiency. Treatment with elemental phosphorus and calcitriol improved her biochemical profile and resolved the rickets. The girl's father had presented with rickets at age 11 months but never received medication. His final height was reduced (154.3 cm; -3.51 SDS), he had undergone corrective leg surgery and had an adult normal phosphate, fibroblast growth factor 23, and iron status. Father and daughter were found to have a heterozygous mutation in exon 3 of the FGF23 gene (c.536G>A, p.Arg179Gln), confirming ADHR.

INTERVENTION: Withdrawal of rickets medication was attempted off and on iron supplementation.

RESULTS: Withdrawal of rickets medication in the girl was unsuccessful in the presence of low-normal serum iron levels at age 5.6 years but was later successful in the presence of high-normal serum iron levels following high-dose iron supplementation.

CONCLUSIONS: We report an association between iron supplementation and a complete loss of biochemical ADHR phenotype, allowing withdrawal of rickets medication. Experience from this case suggests that reduction and withdrawal of rickets medication should be attempted only after iron status has been optimized.

Original languageEnglish
Pages (from-to)3388-3392
Number of pages5
JournalThe Journal of clinical endocrinology and metabolism
Volume100
Issue number9
DOIs
Publication statusPublished - 1 Sep 2015

Keywords

  • Calcitriol
  • Child, Preschool
  • Dietary Supplements
  • Familial Hypophosphatemic Rickets
  • Female
  • Humans
  • Iron
  • Rickets
  • Treatment Outcome
  • Case Reports
  • Journal Article

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